3-1/2 DIGIT A/D CONVERTERS
TC7106
TC7106A
TC7107
1
2
3
4
5
6
7
8
TC7107A
fewer segments are “ON,” each “ON” output drops more
voltage and current. For the best case of six segments (a
“111” display) to worst case (a “1888” display) the resistor
willchangeabout230mW, whileacircuitwithouttheresistor
will change about 470mW. Therefore, the resistor will re-
duce the effect of display dissipation on reference voltage
drift by about 50%.
The change in LED brightness caused by the resistor is
almost unnoticeable as more segments turn off. If display
brightness remaining steady is very important to the de-
signer, a diode may be used instead of the resistor.
APPLICATIONS INFORMATION
Liquid Crystal Display Sources
Several LCD manufacturers supply standard LCD dis-
plays to interface with the TC7106A 3-1/2 digit analog-to-
digital converter.
Manufacturer Address/Phone
Part Numbers1
Crystaloid
Electronics
5282 Hudson Dr.
Hudson, OH 44236
216/655-2429
C5335, H5535,
T5135, SX440
Figure 15. Diode or Resistor Limits Package Power Dissipation
AND
720 Palomar Ave.
Sunnyvale, CA 94086
408/523-8200
FE 0201,0701
FE 0203, 2201
FE 0501
APPLICATIONS INFORMATION
IN
–5V
+5V
Epson
3415 Kashikawa St.
Torrance, CA 90505
213/534-0360
LD-B709BZ
LD-H7992AZ
+
–
1 MΩ
24kΩ
1kΩ
150Ω
Hamlin, Inc.
612 E. Lake St.
Lake Mills, WI 53551
414/648-2361
3902, 3933, 3903
TP3
0.47
µF
0.22
µF
100
pF
0.01
µF
Note: 1. Contact LCD manufacturer for full product listing/specifications.
TP5
TP2
TP1
DISPLAY
0.1
µF
100
kΩ
47
kΩ
Light Emitting Diode Display Sources
Several LED manufacturers supply seven segment
digits with and without decimal point annunciators for the
TC7107A.
40
1
30
TP
4
21
TC7107A
10
20
Manufacturer
Address
Display Type
DISPLAY
Hewlett-Packard
Components
640 Page Mill Rd.
Palo Alto, CA 94304
LED
5.1Ω 1/4W
1N4001
AND
720 Palomar Ave.
LED
Sunnyvale, CA 94086
TELCOM SEMICONDUCTOR, INC.
3-197
TELCOM [ TELCOM SEMICONDUCTOR, INC ]
